Outgoing House member James Tallmadge of New York presents an amendment to the Missouri statehood bill requiring Missouri to halt the further introduction of slaves to the territory and to provide for the gradual emancipation of the slaves already there. Name frequently listed as Talmadge (a 20th century Georgia Senator) and the date occasionally listed as February 14, the day debate began on the amendment)

After several days of sharp debate the House passes the Missouri statehood bill including both parts of the Tallmadge Amendment, marking the first legislation demanding the abolition of slavery. The act is sent to the Senate where the bill is never voted on.

Following a discussion with Franklin Pierce and Secretary of War Jefferson Davis, Douglas releases the Nebraska act with two significant changes: Two terrortories, Kansas and Nebraska will be formed and the Missouri Compromise is superceded and inoperative.

Following the War of 1812 settlers began to enter Missouri in increasing numbers, mostly from Virginia, Kentucky, Tennessee and North Carolina. Although there were petitions for statehood made in 1817, the first petition was presented on the floor of the U. S. House on January 8, 1818. John Scott, Missouri's "Delegate to Congress," presented two additional petitions on February 2 and March 16. Only the second state organized from the massive Louisiana Purchase, Missouri's proposed admission would bring the United States to its most serious Constitutional crises since the founding of the country.

These statehood petitions were passed to the Committee of the Whole, where the vote was effectively postponed because Missouri's admission would give the slaveholding states a majority in the Senate (12 slave -11 free), and 1818 was an election year. Once the election was completed, another petition for statehood was presented on December 18, 1818 by Henry Clay, then Speaker of the House.

Debate on this petition began on the floor of the House in February, 1819. James Tallmadge of New York offered an amendment to the admission bill that said no more slaves would be admitted to the state and children of current slaves would be free when they reached the age of 25, reflecting the belief of gradual emancipation.

Nobody was prepared for either the debate or reaction. First, the amendment was broken into two parts so that they could be considered separately. Surprisingly, both portions of the Tallmadge amendment passed in the House. The bill then went to the Senate, where the chamber was equally divided, slave and free. Here, Southern Senators argued that Congress had no power to to exclude slavery from Missouri. Rufus King, Senator from New York and a signer of the Constitution, argued that the Constitution did not restrict Congress. William Pinckney of Maryland, also a signer of the Constitution, effectively argued that the admittance of new states needed to be as equals of the original states, which he interpreted as meaning the states had the right to self-determination on the issue of slavery.

Concern for the plight of the slave swept through the North, surprising almost every politician in Washington D. C.. State houses throughout the South passed resolutions backing the addition of Missouri as a slave state. The West, only recently coming into the sectional disputes, tended to side with the South, perhaps not being pro-slave but rather being for the free entry of territories into the Union. Once again, the bill died in Congress.

The prior inaction of Congress moved consideration of the bill to the Sixteenth Congress, which convened in December, 1819. The House still had support for the Tallmadge Amendment and the Senate had the votes to kill any admittance bill passed with the anti-slavery amendment attached. Maine then applied for statehood and Congress agreed to admit the two states without restriction, although everybody involved realized Maine would enter the Union as a free state and Missouri would enter the Union as a slave state.

Senator Jesse Thomas of Illinois then proposed restricting slavery in the Louisiana Purchase to a line south of 36 30 with the exception of Missouri (36 30 is the southern line of Missouri in the west). This is what is generally known as the Missouri Compromise. Henry Clay added a required exclusionary clause, which Missouri had to amend to its state constitution, recognizing free blacks as citizens and not slaves (it "excluded" them from being treated as slaves).

In spite of the "compromise," many Southerners did not support the measure. They realized that only one slave state (Arkansas) would be created from the Louisiana Purchase but many more free states could be carved out of the land. Southern senators who accepted the compromise traded long-term problems for short-term stability with the hopes that calmer heads would be able to work out an equitable solution.